Berlin 2012 – wissenschaftliches Programm

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DF: Fachverband Dielektrische Festkörper

DF 13: Poster II

DF 13.23: Poster

Mittwoch, 28. März 2012, 15:00–17:30, Poster E

Size-dependent optical properties of polar oxide BaTiO₃ nanocrystals applied for cell imaging — •Pia Bäune¹, Mirco Imlau¹, Karsten Kömpe², and Jacob Piehler² — ¹Fachbereich Physik, Universität Osnabrück — ²Fachbereich Biologie/Chemie, Universität Osnabrück, Germany

Polar oxide nanocrystals have been introduced as novel class of optical markers for cell imaging in biophotonics. Based on frequency conversion they obey interesting, outstanding properties in comparison with imaging techniques via fluorescence and resonance spectroscopy. For instance, pump- and probe-photon energies are spectrally separated, the crystals show no photobleaching and/or photoblinking, and coherent light is generated with anisotropic radiation characteristics. Thus, polar oxide nanocrystals are promising candidates for continuous three-dimensional detection of both position and orientation of markers in biological cells. In this contribution we present our studies on the size-dependent optical properties of BaTiO₃ nanocrystals by means of frequency conversion techniques. BaTiO₃ nanocrystals have been synthezised with colloidchemical methods taking hydrothermal and solvothermal methods for bulk crystal growth into account. We focus on photodegradation phenomena that relate to the nanocrystal surfaces as a function of nanoparticle size. Our results are compared with BaTiO₃ bulk crystals with respect to SHG efficiency and the processes of laser-induced surface damages. Surface modification by SiO₂ or polymers (PEG, PVB) is proposed and discussed taken the physiological environment in cells into account.